Improvement in furnaces for steam-boilers



CHARLES J. HARRIS.

improvement in Furna-ces fo'rsteam iBoilers.

Witnesses- I I I hventbr R I Patented Oct. 3, 1871.

PATENT QFFICE.

CHARLES J. HARRIS, OF BLOOMDTGTON, ILLINOIS.

IMPROVEMENT IN FURNACES FOR STEAM-BOILERS.

Specification forming part of Letters Patent No. 119,605, dated October3, 1871.

To all whom it may concern:

Be it known that 1, CHARLES J. HARRIS, of Bloomington, in the county ofMcLean and in the State of Illinois, have invented certain new anduseful Improvements in Furnaces for Steam-Boilers; and do hereby declarethat the following is a full, clear, and exact description thereof,reference being had to the accompanying drawing and to the letters ofreference marked thereon making a part of this specification.

The nature of my invention consists in an auxiliary grate, arranged inrear of and below the ordinary grate of furnaces for steam-boilers, thebars of the ordinary grate being hollow to supply air to the rearcompartment; and also in conveying the exhaust steam from the engineunder this auxiliary grate through the live cinders and into that partof the fire-box, all of which will be hereinaftermore fully set forth.

In order to enable others skilled in the art to which my inventionappertains to make and use the same,I will now proceed to describe itsconstruction and operation, referring to the annexed drawing, in which-Figure l is a longitudinal vertical section; Fig. 2, a View from theunder side; and Fig. 3, afront view of a return-flue boiler with myimprovements attached.

Although I have in the drawing represented my improvements as attachedto a furnace for a horizontal return-fine and tubular boiler, they maybe applied to almost any or every kind of furnaces where the same may beof advantage.

A represents a horizontal return-fine or tubular boiler, with thefire-box B beneath the front end. In this fire-box is the usual grate O,composed of hollow grate-bars, upon whichthe fire is built. D representsa grate or set of grate-bars fixed across the furnace in rear of theordinary grate O. This auxiliary grate is placed about eight inchesbelow the other, for the purpose of pushing all the dirt and livecinders back instead of raking them out in front. By this means fuel issaved, and also the danger obviated of burning the firemen while rakingtheir fires. The gratebars composing the ordinary fire-grate O terminatejust above and at the side of the rear compartment of the fire-box, and,being hollow, ad

mit of a passage of air from the front of the main entrance to the spaceabove the rear grate. This air will thus be discharged where it willtend to burn up the smoke from the burning-fuel on the front grate, andwill supply the rear compartment of the fire-box with air to keep aliveand consume the fuel and smoke from the fire on the rear grate.

This also keeps the grate-bars in front from burning out. Thesegrate-bars should be flush, or nearly so, with the front surface of thefurnace. These tubes can then be closed, orpartly closed, as deemedadvisable, by means of a sliding draughtdamper perforated with holes tocorrespond in distance and dimensions with the hollow gratebars ortubes.

In a recent patent granted to me for improvement in return-fl ue boilersI described and claimed conveying the exhaust steam from the engine bymeans of a suitable pipe to or near the rear end of the boiler to cleanthe same and create a draught. From this pipe I conduct the exhauststeam, or rather a portion thereof, by means of a pipe, E, under theauxiliary or rear grate D. The end of this pipe is provided with anumber of slots or openings, to admit of the escape of the exhaust steamin many directions through the live cinders and into that part of thefire-box for the purpose of increasing the heat.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is

1. In a furnace'for steam-boilers, the combination of the grates O andD, the latter being arranged in rear of and below the former, andtheformer composed of hollow bars to convey the outside air to and abovethe rear grate, all substantially as and for the purposes herein setforth.

2. The combination, in a furnace for steamboilers, of the grates O andD, constructed and arranged as described, and a pipe for conveying theexhaust steam from the machinery to and beneath the rear grate D,substantially as and for the purpose herein set forth. 4

In testimony that I claim the foregoing I have hereunto set my hand this13th day of July, 1871.

CHARLES J. HARRIS.

Witnesses Tnos. SLADE,

